Ken12

"Domestic water" as opposed to drinking water or?? Plate exchanger?? Sorry guys, I wondered into the 2 Apollo's 17 years ago fat, dumb and happy. Changed out a filter yearly, have noticed a small leak in the bottom of the casing that stopped before I even had to deal with it and have had the return pump making noise when it kicks on for far too long. That's all I know about the system. Appreciate the advice. Attached pics should give you some idea of the upper floor system that has been used the most in the past 17 years we've had it. Pic #1 is in kitchen. Pic #2 is on the opposite side of same wall in garage where the heat exchanger is installed. Click to Enlarge 39.02 KB Click to Enlarge 37.91 KB

Upstairs gets hammered the most - showers, dishwaher, sinks, toilets and unit connected to A/C. Downstairs excavated rooms/kitchen just have one shower and kitchen sink, no A/C needed. Click to Enlarge 36.24 KB

Moved into the 2 level 3,000 sq ft home in '93. One Apollo unit on each level, each with 50 gal Apollo water heater--circ 1986, probably when the house was changed out from radiant heat to hydro-heat system. The system has worked well, but in recent years the upper unit has developed a vibration noise on the return end (probably the Grundfos up15-42su return pump) that is annoying. Also, there was that common problem of a small leak at the heat coil/intake pipe, but it actually stopped of its own accord years ago Wayyyyyy overdue to replace the water heaters. No one, I mean no one wants to work on these units. Drop 10k on gas or 3k on two water heaters and new return pump???? Opinions appreciated